#include<iostream>
#include<cstring> 
using namespace std;

int Findstr(char s1[] , char s2[]) {
	int len1 = strlen(s1);
	int len2 = strlen(s2);
	if(len2 == 0) return 0;		//空串返回0
	int i = 0;
	int j = 0; 
	while(s1[i]!='\0' && s2[j]!='\0') {
		if(s1[i] == s2[j]) {
			i++;
			j++;
		}
		else
		{
			i = i-j+2;
			j = 0;
		}
	}
	if(s2[j]=='\0') return i-len2+1;
	else return -1;
}

int main() {
	char s1[100];
	char s2[10];
	cin >> s1 ;
	cin >> s2 ;
	cout << Findstr(s1,s2);
	return 0;
}